Why people with Parkinson’s disease may want to put on their dancing shoes

BY Judy Martin Finch

A neurodegenerative disease such as Parkinson’s unfortunately signals a long, slow decline in motor skills. Surprisingly, however, a physical activity as complex as dancing the tango could possibly reverse the decline.

“Within the context of the dance, people with Parkinson’s get to practice again and again things they have trouble with, without realizing they’re actually practicing,” says Gammon Earhart, who has seniors dancing for fun, exercise and intriguing improvements in their functional abilities.

It is fitting that Gammon Earhart began her research career working with a device that resembles a giant turntable. Music — tango music in particular — has become an important component of her work with Parkinson’s disease.

Earhart, PT, PhD, associate professor of physical therapy, neurology and neurobiology, used a rotating treadmill for studies on healthy people while she was a postdoctoral researcher at Oregon Health & Science University. Her research demonstrated that when people walk on a rotating surface for a period of time, then step off, they are unable to walk in a straight line. The process forces them to turn.

She took her research to Washington University School of Medicine when she joined the faculty of the Program in Physical Therapy in July 2004. She began working with people with Parkinson’s disease, a chronic and progressive movement disorder that involves the malfunction and death of neurons. As the disease progresses, people are unable to control movement normally.

“Turning is something that people with Parkinson’s disease are particularly troubled by,” says Earhart, a member of the Movement Disorder Center in neurology. “They try to make a turn but get stuck and feel like their feet are glued to the floor. That can lead to falls and the consequences related to falls.”

One of her key goals is to help them make turns. “It was that interest in turning behavior — in healthy people and in Parkinson’s patients — that eventually led me to the dance floor,” she says.

In 2005, Earhart attended a Society for Neuroscience meeting and saw Canadian researchers present an abstract focused on frail, elderly individuals randomly assigned either to walk in a group for exercise or learn to dance the tango. The researchers’ findings indicated that those assigned to dance had improved their balance more than those assigned to walk.

When Madeleine Hackney, PhD ’09, a professional dancer turned graduate student, began working in Earhart’s lab, it gave Earhart an idea.

“I thought, ‘Madeleine can certainly do the tango.’ And after talking to her, Madeleine agreed that we should try a pilot study incorporating the dance for people with Parkinson’s,” she recalls.

It proved difficult to recruit patients at first. Many thought they couldn’t dance — especially the tango — with a disease as limiting as Parkinson’s. But eventually enough patients were recruited, and the pilot study went well.

“The participants were pleasantly surprised at how much they could still do, and they enjoyed it,” Earhart says. “And our outcome measures showed that, when compared with a group of people who had taken a traditional exercise class, there were more significant improvements regarding balance and walking in the people in the tango group.”

Encouraged and excited by the results, Earhart and Hackney moved forward with their research.

“We noted that ... the people who were participating in tango dancing were improving instead of deteriorating, which is unexpected for people with a neurodegenerative disease like Parkinson’s.” — Gammon Earhart, PT, PhD

Subsequent studies have included 10 days of classes over two weeks, which the researchers refer to as “Tango Boot Camp,” to a study that offered classes twice a week for a full year. The most typical design, however, offers classes twice a week for three months.

Their findings have shown that tango-dancing patients experience improvements that are as good as or better than those who exercise using other forms of dance, such as the waltz or fox-trot, or alternative approaches, such as T’ai Chi.

Earhart theorizes that tango’s benefits come from incorporating specific movements that people with Parkinson’s often have difficulty performing, such as walking backward.

The most important finding has come from the yearlong study. Participants were evaluated before they started dancing and then again after three months, six months and 12 months. This group was compared with another group of people who had Parkinson’s but were not exercising over the same time period.

“We noted that at three months and then again at six and then 12 months, the people who were participating in tango dancing were improving instead of deteriorating, which is unexpected for people with a neurodegenerative disease like Parkinson’s,” Earhart says. “That suggested we were potentially modifying the trajectory of the disease’s progression with participation in the tango exercise program. That could have very positive ramifications.”

Earhart noted other improvements in the study participants’ lives, as well. Some picked up activities they previously had given up, and some engaged in new social activities. Increased activity did not occur in the non-dancing group.

Susan Deusinger, PT, PhD, FAPTA, director of the Program in Physical Therapy, says that Earhart “has emerged as a leader in understanding the neurological foundation of movement and how degenerative diseases of the brain affect movement, health and function in daily life. While her work is especially important for patients with Parkinson’s disease, it also represents a line of inquiry that blends basic and applied themes in creative and innovative ways.”

In a new study, supported by a recent $1.5 million grant from the National Institute of Neurological Disorders and Stroke, Earhart will compare tango dancing to walking on a treadmill. She plans to control for social factors as much as possible by arranging the treadmills in clusters so participants can talk to one another, as dance partners do.

In addition to evaluating each participant’s gait, balance, cognitive function, severity of disease and quality of life, Earhart will utilize neuroimaging with functional MRI (fMRI) as part of the study.

Joel Perlmutter, MD, professor of neurology, radiology, neurobiology, physical therapy and occupational therapy, has a database that includes more than 2,400 Parkinson’s patients, some of whom may be potential candidates for Earhart’s study, which calls for 120 participants.

“We hope to determine whether brain activity or brain connections change as a result of participating in the exercise programs, and whether the changes that result from tango dancing are the same as or different from the changes that result from using a treadmill,” Earhart says. “We want to determine whether the changes we see in the brain are related to changes in physical performance.”

Earhart says her research would be more difficult, if not impossible, if she were somewhere other than the School of Medicine. “There’s no way we could involve so many participants without the resources provided through the Movement Disorder Center and the Greater St. Louis American Parkinson Disease Association.”